Reverse rim sign (kidney)

The reverse rim sign describes relative hypoenhancement of the renal cortex and normal enhancement of the renal medulla on contrast-enhanced CT and MRI. This enhancement pattern can also be visualized using CEUS .

It is a typical finding of renal cortical necrosis that may occur in the setting of renal transplant rejection, intravascular hemolysis, shock, and as an obstetric complication .